Kotlin Coroutines with returning value

Question

I want to create a coroutine method which has returning value.

For example)

fun funA() = async(CommonPool) {
    return 1
}

fun funB() = async(Commo         


        

Answer 1

Here is the way I did it, to return a Boolean value when trying to delete a phone number from my Room database. You can use the same pattern for what you are trying to accomplish. In my view model:

private var parentJob = Job()
private val coroutineContext: CoroutineContext get() = parentJob + Dispatchers.Main
private val scope = CoroutineScope(coroutineContext)

suspend fun removePhoneNumber(emailSets: EmailSets, personDetails: PersonDetails) : Boolean  {
    var successReturn = false
    scope.async(Dispatchers.IO) {
        val success = async {removePhoneNumbersAsync(emailSets,personDetails)}
        successReturn = success.await()

    }
    return successReturn
}

fun removePhoneNumbersAsync(emailSets: EmailSets, personDetails : PersonDetails):Boolean {
    var success = false
    try {
        val emailAddressContact = EmailAddressContact(emailSets.databaseId, personDetails.id, personDetails.active)
        repository.deleteEmailAddressContact(emailAddressContact)
        val contact = Contact(personDetails.id, personDetails.personName, personDetails.personPhoneNumber, 0)  
        repository.deleteContact(contact)
        success = true
    } catch (exception: Exception) {
        Timber.e(exception)
    }
    return success
}

In my Activity:

runBlocking {
    if (v.tag != null) {
            val personDetails = v.tag as PersonDetails
            val success  = viewModel.removePhoneNumber(emailSets,personDetails)
            if (success) {
                val parentView = v.parent as View
                (parentView as? TableRow)?.visibility = View.GONE
                val parentViewTable = parentView.parent as ViewGroup
                (parentViewTable as? TableLayout)
                parentViewTable.removeView(parentView)
            }
     }

}